Electromagnetic relay



E. FRYDMAN ELECTROMAGNETIC RELAY Filed Oct. 17, 1946 INVENTOR EMANUEL FRYDMAN ATTORN EY Patented Feb. 28, 1950 ELECTROMAGNETIC RELAY Emanuel Frydman, Liverpool, England, assignor to Automatic Telephone & Electric Company Limited, Liverpool, England, a British company Application October 1'7, 1946, Serial No. 703,900 In Great Britain December 18, 1945 4 Claims. 1

The present invention relates to electromagnetic relays and to mountings therefor and is more particularly concerned with relays of the miniature type.

One of the objects of the invention is to provide an improved construction for the relay which facilitates its mounting within a completely closed housing so that the relay contacts are kept free from dust and oxidation.

According to the invention the relay is mounted within an hermetically sealed envelope and a plurality of parallel members maintained in fixed relation to each other by insulating discs which serve to locate the assembly within the envelope are provided for supporting and/or effecting electrical connections to the relay.

Preferably, according to a feature of the invention, the parallel members terminate outside the envelope in pins, the positional relation between which is such that the pins are adapted for insertion in a suitable socket of the type employed, for instance, in the mounting of thermionic valves.

It will be appreciated that the ordinary type of electromagnetic relay could with some modification be enclosed within a housing but such an arrangement would occupy considerable space and a completely enclosed relay only become an attractive proposition if the space taken up by such a relay does not greatly exceed that taken up .1

by an ordinary unenclosed relay. A relay suitable for mounting within a completely closed housing should thus be of the miniature type and, according to a further feature of the invention, in such a relay, electrical connection with the electromagnet is effected by parallel conducting members which also serve to support the electromagnet. Further, according to another feature of the invention, the armature is supported by at least one conductor which forms the lever spring of a contact set. According to yet another feature of the invention, two contact sets are employed and the lever springs are formed of parallel members which support the armature in the correct position relative to the electromagnet. This embodiment is a convenient one in that there are eight current-carrying conductors to be taken to the relay and the positional relation between them may be so arranged as to enable the housing to be inserted in a come mercial eight-point thermionic valve socket.

The invention will be better understood from the following description of one embodiment taken in conjunction with the accompanying 2 drawing which shows a miniature relay mounted within a glass housing.

Referring to the drawing, the electromagnet ll is mounted in a rigid framework comprising mica discs H, I2 and metallic spacing rods [3, l4 and [5 which pass through eyelets 16 in the disc. The electromagnet is secured electrically and mechanically to the two rods l4 and 15 by means of suitable clips I! and I8 respectively. The electromagnet is provided with a U-shaped core [9, the poles of which extend to a position close to the armature 20. As shown in the drawing, the rela is provided with two changeover springsets, and the lever springs 2| and 22, which may be made of silver, are welded to the currentcarrying conductors 23 and 24. The armature 20, which may be made of thin soft iron or steel suitably plated or fitted with non-magnetic studs to minimise the effect of residual magnetism, is mounted on but insulated from the two lever springs 2i and 22 by turning over the sides of the armature to clamp on the two lever springs, the latter being insulated with mica at the clamping positions. The make and break springs 25 are preferably L-shaped and may be of silver.

During manufacture the rigid frame work is first assembled with the electromagnet and armature in position. The ends of the eight current-carrying conductors are then welded to eight pins 26 which pass through a glass base plate 21. Finally the glass envelope 28 is fused to the base plate 21 and the unit may be evacuated by employing electronic tube technique and filled with an inert gas.

It will be appreciated that the invention is not limited to the precise construction shown and in particular other types of spring sets and other types of electromagnets, for instance, two coil electromagnets, may be employed. Thus a single make or break set may be employed in which case the member 2|, say, will then be a purely mechanical support for the armature 2D. In such a case there will only be four pins in the base and a suitable four pin valve socket could be employed. Other combinations are also possible and where the number of pins is between 4 and 8, the standard 8-pin valve socket may be used.

I claim:

1. A circuit controlling device comprising a hermeticall sealed tube, a pair of discs spaced apart in said tube, a pair of metallic members extending in parallel relation between said discs, a magnet supported by said members and having the ends of its windings connected respectively to said members, a second pair of metallic members supported on one of said discs supporting an armature adjacent one pole of said magnet, contacts supported by the other of said discs, said magnet, when energized, causing movement of said armature to thereby cause engagement of said second members with certain of said contacts to complete a circuit.

2. A circuit controlling device such as claimed in claim 1 in which all of said members have extensions terminating in plug contacts outside of said tube.

3. A circuit controlling device including a unitary structure enclosed within a hermetically sealed tube, said structure consisting of a pair of discs of insulating material spaced apart and held in parallel relation by a pair of rods of conducting material, a magnet supported in bridge of said rods and having an end of its winding connected to each rod, a pair of flexible wires extending from one of said discs and supporting an armature in bridge thereof but insulated therefrom and adjacent the pole of said magnet, other flexible leads extending from the other disc and in the path of said pair of flexible wires,

energization of said magnet causing flexing of said pair of wires to engage said other flexible leads through attraction of said armature.

4. A circuit controlling device as claimed in claim 3 in which said rods and said flexible wires each have extensions terminating in plug terminal-s outside said tube.

EMANUEL FRYDMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,194,194 Kubach et a1 Aug. 8, 1916 1,194,281 Doane Aug. 8, 1916 1,702,490 Brach Feb. 19, 1929 2,192,506 Ruben Mar.,5, 940 2,391,668 Austin Dec. 25, 1945 FOREIGN PATENTS Number Country Date 476,457 Great Britain Dec. 9, 1937 

